The present invention relates to a gas washing or purging stone or sink including a gas permeable refractory inner brick portion, a gas impermeable refractory outer brick portion surrounding the inner brick portion, and a gas distribution chamber. The present invention also relates to an assembly of such gas washing or purging stone or sink and a closure member having an integral gas inlet connection and detachably connected to or mounted against the gas purging or washing stone or sink to close the gas distribution chamber.
Gas purging, flushing or washing stones or sinks are used for introducing gas through a metallurgical vessel into a molten metal therein, for various purposes as would be understood by one skilled in the art. For example, such devices are disclosed in DE-PS 36 23 609 (corresponding to U.S. Pat. No. 4,779,849). In known such devices the gas distribution chamber is closed by means of a bottom plate that is permanently connected to the gas washing stone or sink, with a gas inlet connection being integral with such bottom plate. To form the gas distribution chamber, the bottom plate must be mounted and maintained at a specific distance from the gas permeable refractory inner brick portion of the gas washing sink. Thus, this known gas washing sink includes a number of integral metal parts and therefore is expensive. When the gas washing sink must be replaced, as inevitably occurs, the bottom plate and gas inlet connection also must be replaced since they are integral components of the gas washing sink, even though such metal components could be used again. This is an inherently expensive practice.